package org.csu.mypetstore.service;

import org.csu.mypetstore.domain.Verify;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class VerifyService {
    Verify verify;
    public VerifyService(){
        verify = new Verify();
        verify.setW(70);
        verify.setH(35);
        verify.setR(new Random());
        // {"宋体", "华文楷体", "黑体", "华文新魏", "华文隶书", "微软雅黑", "楷体_GB2312"}
        verify.setFontNames(new String[]{"宋体", "华文楷体", "黑体", "微软雅黑", "楷体_GB2312"});
        // 可选字符
        verify.setCodes("0123456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ");
        // 背景色
        verify.setBgColor(new Color(255, 255, 255));
    }

    private Color randomColor () {
        int red = verify.getR().nextInt(150);
        int green = verify.getR().nextInt(150);
        int blue = verify.getR().nextInt(150);
        return new Color(red, green, blue);
    }

    // 生成随机的字体
    private Font randomFont () {
        int index = verify.getR().nextInt(verify.getFontNames().length);
        String fontName = verify.getFontNames()[index];//生成随机的字体名称
        int style = verify.getR().nextInt(4);//生成随机的样式, 0(无样式), 1(粗体), 2(斜体), 3(粗体+斜体)
        int size = verify.getR().nextInt(5) + 24; //生成随机字号, 24 ~ 28
        return new Font(fontName, style, size);
    }

    // 画干扰线
    private void drawLine (BufferedImage image) {
        int num  = 3;//一共画3条
        Graphics2D g2 = (Graphics2D)image.getGraphics();
        for(int i = 0; i < num; i++) {//生成两个点的坐标，即4个值
            int x1 = verify.getR().nextInt(verify.getW());
            int y1 = verify.getR().nextInt(verify.getH());
            int x2 = verify.getR().nextInt(verify.getW());
            int y2 = verify.getR().nextInt(verify.getH());
            g2.setStroke(new BasicStroke(1.5F));
            g2.setColor(Color.BLUE); //干扰线是蓝色
            g2.drawLine(x1, y1, x2, y2);//画线
        }
    }

    // 随机生成一个字符
    private char randomChar () {
        int index = verify.getR().nextInt(verify.getCodes().length());
        return verify.getCodes().charAt(index);
    }

    // 创建BufferedImage
    private BufferedImage createImage () {
        BufferedImage image = new BufferedImage(verify.getW(), verify.getH(), BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = (Graphics2D)image.getGraphics();
        g2.setColor(this.verify.getBgColor());
        g2.fillRect(0, 0, verify.getW(), verify.getH());
        return image;
    }

    // 调用这个方法得到验证码
    public BufferedImage getImage () {
        BufferedImage image = createImage();//创建图片缓冲区
        Graphics2D g2 = (Graphics2D)image.getGraphics();//得到绘制环境
        StringBuilder sb = new StringBuilder();//用来装载生成的验证码文本
        // 向图片中画4个字符
        for(int i = 0; i < 4; i++)  {//循环四次，每次生成一个字符
            String s = randomChar() + "";//随机生成一个字母
            sb.append(s); //把字母添加到sb中
            float x = i * 1.0F * verify.getW() / 4; //设置当前字符的x轴坐标
            g2.setFont(randomFont()); //设置随机字体
            g2.setColor(randomColor()); //设置随机颜色
            g2.drawString(s, x, verify.getH()-5); //画图
        }
        verify.setText(sb.toString());

        drawLine(image); //添加干扰线
        return image;
    }

    // 返回验证码图片上的文本
    public String getText () {
        return verify.getText();
    }

    // 保存图片到指定的输出流
    public static void output (BufferedImage image, OutputStream out)
            throws IOException {
        ImageIO.write(image, "JPEG", out);
    }
}
